Conventionally, negative output regulator circuits that generate a desired negative voltage based on an input voltage are widely known, and various technologies have been disclosed and proposed relating to them.
For example, patent document 1 discloses and proposes a technology in which a power transistor is connected in series with a negative power source line. In response to an error signal generated by an error amplifying circuit that depends on the difference between an actual output voltage and a reference voltage. the base current of the power transistor is controlled. Thus it is possible to perform on-off control with a positive potential in a negative output regulator circuit that obtains a desired negative output voltage.
The patent document 1: JP-A-H11-327669